IgG4-related disease (IgG4-RD) is a multi-organ inflammatory immune-mediated illness caused by IgG4-secreting plasma cells infiltrating the tissue. This condition usually affects elderly men. A 90-year-old Chinese male was diagnosed with IgG4-RD based on the new 2019 ACR/EULAR classification criteria, as he had multiple organ involvement. After receiving treatment with glucocorticoids, leflunomide, and gamma-globulin, the patient\'s clinical symptoms significantly improved, confirming the accuracy of the diagnosis. The patient had an 18-year medical history during which the disease progressively worsened due to delayed diagnosis and treatment. Although the relevant symptoms were alleviated with appropriate medication, the overall treatment process encountered challenges. Due to the patient\'s relative lack of adrenocortical function, he experienced symptoms such as nausea, exhaustion, and loss of appetite during the hormone reduction process. Therefore, timely intervention is especially crucial to address the side effects of hormone therapy.

An asymptomatic 75-year-old man who underwent transverse colon cancer surgery two years previously presented with retroperitoneal fibrosis (RPF) around the ventral sacral and right external iliac artery and vein on abdominal computed tomography (CT) during a routine surveillance visit. We assumed cancer recurrence or immunoglobulin G4 (IgG4)-related disease (RD), but although generic tumor markers and IgG4 levels were normal, soluble interleukin 2 receptor (sIL-2R) was elevated at 569 U/mL (reference: 122-496 U/mL). No diagnosis was made at this time, and the patient was followed up. He subsequently developed edema of both lower extremities. Abdominal enhanced CT showed an enlarged RPF without invasion of surrounding organs and with a delayed contrast effect, and positron emission tomography-CT showed fluorodeoxyglucose accumulation in the same area but a lower standardized uptake value (SUV) than at the time of transverse colon cancer diagnosis. Although generic tumor markers and IgG4 levels remained within the reference range, sIL-2R was further elevated to 1100 U/mL. An open biopsy and histopathology showed a high IgG4/IgG-positive cell ratio and infiltration of IgG4-positive plasma cells. The patient was finally diagnosed with IgG4-RD RPF. In cases of RPF after colorectal cancer surgery, the combined findings of elevated sIL-2R, lack of infiltration into surrounding organs, and lower SUV values ​​than at the cancer site could provide useful information to aid the diagnosis of IgG4-RD RPF.

Retroperitoneal fibrosis (RPF), also referred to as Ormond\'s disease, is a rare fibroinflammatory condition characterized by abnormal fibrous tissue deposition in the retroperitoneal space, which traditionally presents with ureteral obstruction. Nonetheless, our case report showcases an exceptional instance involving a 70-year-old female patient who presented with symptoms suggestive of colonic obstruction, an unusual presentation that is not commonly associated with RPF. Although RPF has established associations with autoimmune conditions such as immunoglobulin G4-related disease and systemic lupus erythematosus, its connection to colonic obstruction remains undocumented in the medical literature. Our patient is a 70-year-old female who presented with constipation, anemia, and fecal occult blood. Her past medical history included a hysterectomy due to fibroids, right breast lumpectomy, type 2 diabetes mellitus, subclinical hyperthyroidism, hypertension, and obesity. Upon physical examination, the patient\'s abdomen appeared protuberant but was non-tender to palpation. Bowel sounds were normal, and there was no distension. Notably, there was no tenderness in the right or left costovertebral angles, nor was there any guarding. Workup with colonoscopy could not be completed due to the inability to pass a colonoscope beyond the rectosigmoid junction. Further workup with barium enema confirmed an apple core lesion seen in the rectosigmoid concerning for a neoplastic or inflammatory process. Finally, a computed tomography scan of the abdomen and pelvis showed a 7.1 cm right pelvic mass attached to the bladder and cecum, moderate right hydroureteronephrosis, and a 5.2 cm left adnexal mass with soft tissue changes narrowing the sigmoid colon. The next step was to take the patient for an exploratory laparotomy. During exploratory laparotomy, extensive adhesions and desmoplastic reactions were observed in the pelvic region, involving the sigmoid colon, bladder, cecum, and appendix. Two firm masses were identified in the retroperitoneum, one located in the left lower quadrant (LLQ) adherent to the posterior wall of the sigmoid colon and one in the right lower quadrant (RLQ) adherent to the posterior wall of the cecum. Three specimens were sent to pathology for further examination: a portion of the sigmoid colon, a resection from the RLQ mass, and a resection from the LLQ mass. Pathology reported dense fibrotic masses with abscess-like formation, reactive in nature and of unclear etiology, and negative for malignancy. They were negative for fibromatosis (β-catenin negative), and IgG4+/IgG+ was approximately 5%. Interestingly, the LLQ mass also contained remnants of the fallopian tube and ovary and benign cystic changes. This case report presents a unique and atypical presentation of RPF, deviating from the conventional presentation of ureteral obstruction. The patient\'s initial symptoms suggested colonic obstruction, a clinical scenario rarely linked to RPF. This case underscores the significance of considering diverse clinical presentations when diagnosing RPF, thereby expanding our comprehension of the condition\'s clinical spectrum and ultimately refining patient care and management.

Retroperitoneal fibrosis, a rare and often idiopathic condition, poses significant diagnostic challenges. While most cases are considered idiopathic or immune-mediated, a small but important proportion are associated with malignant neoplasms, with implications for prognosis and management. The present study describes the case of a 69-year-old man who presented to the emergency department of the Virgen de las Nieves University Hospital (Granada, Spain), with a 2-week history of epigastric pain, vomiting and altered bowel habits. Laboratory investigations revealed previously undiagnosed renal insufficiency. An abdominal computed tomography (CT) scan showed extensive diffuse retroperitoneal infiltration extending from the periduodenal region to the pubic bone, resulting in gastric dilatation and hydronephrosis. A CT-guided retroperitoneal biopsy was performed and pathology confirmed the presence of urothelial carcinoma. This diagnosis led to the initiation of a chemotherapy regimen consisting of carboplatin and gemcitabine specifically designed for urothelial carcinoma. A follow-up 18F-FDG PET scan performed 6 months later showed a partial functional response. This case illustrates a rare presentation of urothelial carcinoma masked by extensive retroperitoneal fibrosis, and highlights the importance of accurate diagnosis in reducing tumor burden and improving the clinical status of patients.

IgG4-related diseases are adverse events that occur after receiving treatment with immune checkpoint inhibitors (ICI). This study reports the first case of IgG4-related retroperitoneal fibrosis after the administration of chemotherapy with nivolumab and ipilimumab (NI therapy). An 80-year-old man developed lower abdominal pain eight months after NI therapy was initiated. Although the primary lesion maintained its reduced size on computed tomography, there was an increase in the soft tissue shadows intensity around the abdominal aorta, bladder, and seminal vesicles, suggesting retroperitoneal fibrosis. Blood tests showed elevated IgG4 levels. Computed tomography-guided biopsy of the retroperitoneum showed B cell-dominant lymphocyte infiltration consistent with IgG4-related retroperitoneal fibrosis and characteristic CD8-positive lymphocyte infiltration, suggestive of the involvement of cytotoxic T cells. Based on the clinical, imaging, and pathological findings, the patient was diagnosed with IgG4-related retroperitoneal fibrosis due to ICI. Immunotherapy discontinuation alone did not result in improvement; therefore, steroid therapy was initiated. In clinical practice, IgG4-related retroperitoneal fibrosis can occur as an immune-related adverse event when administering anti-PD-1 and anti-CTLA-4 antibodies for cancer immunotherapy. Early steroid therapy could be effective in controlling this immune-related adverse event.

暂无摘要。

Retroperitoneal fibrosis (RPF) is a rare condition characterized by systemic inflammation and the proliferation of fibroinflammatory tissues in the retroperitoneum. It may lead to the formation of a retroperitoneal mass and can encase the aorta, its branches and ureters. The pathogenesis of RPF is not fully known. We report a case of a 52-year-old male presented with low back ache, flank pain, swelling of legs, oliguria and features of obstructive uropathy, later diagnosed to be RPF. The mainstay of diagnosis includes blood workup, imaging and biopsy. The first line of treatment is corticosteroids. Surgical intervention is carried out when medical measures have failed or when contraindicated. Early diagnosis and prevention of complications is the key, and a high degree of suspicion is needed.

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a multi-organ immune-mediated fibroinflammatory disorder that may imitate malignancy, infectious or any other inflammatory disorder. IgG4-related retroperitoneal fibrosis (IgG4-RPF) is a rare form of IgG4-RD, diagnosis of which is often relied on radiological technology. Herein, we describe a case of 60 year old male, presenting with low back pain and weight loss for a period of 2 months and 15 days. Imaging studies showed a retroperitoneal tumorous mass along with bilateral hydroureteronephrosis, which was later confirmed to be IgG4-related retroperitoneal fibrosis on the basis of extensive histopathological analysis. Immunosuppressive therapy resulted in a decrease in fibrosis and restoration of renal function.

IgG4-related retroperitoneal fibrosis is a rare cause of renal dysfunction that usually manifests as obstructive nephropathy (sometimes with extrarenal manifestations). Due to the non-specific symptoms at the onset of the disease and often latent course, special laboratory and instrumental examination methods are usually needed to establish a diagnosis. The article describes a clinical case of a relapse of IgG4-related retroperitoneal fibrosis in a 53-year-old patient, who developed bilateral ureterohydronephrosis with postrenal acute kidney injury after the withdrawal of glucocorticoid therapy. The patient underwent bilateral percutaneous nephrostomy and resumed glucocorticoids at a dose of 30 mg/day. Postobstructive diuresis was 22 L. Treatment resulted in a complete normalization of the creatinine level and transient hypokalemia, which was eliminated with potassium medications. At the final stage of the treatment, bilateral stenting of both ureters was performed with a tapering of glucocorticoids to 5 mg per day with CT control of the retroperitoneal space after 5 months. A clinical case demonstrates that an interruption of glucocorticoid treatment in patients with IgG4-related retroperitoneal fibrosis can lead to ureterohydronephrosis with the development of acute kidney injury. In such cases, stenting of the ureters could be considered an optimal therapeutic option.

Essential thrombocythemia (ET) is associated with an increased risk of thrombosis and autoimmune renal involvement. We report an extremely rare case of an acute kidney injury (AKI) in the presence of bilateral renal pelvises fibrosis in a patient with a proven diagnosis of ET. A 48-year-old male patient with a past medical history of mild chronic kidney disease and ET was admitted to our hospital with AKI. The patient discontinued his hydroxyurea treatment for the past 2 months and laboratory data showed increasing serum creatinine levels and platelet counts with increased renal sizes, severe hydrocalyx, and bilateral renal sinuses\' fibrosis in imaging. The patient started again on hydroxyurea therapy and showed improvement in all laboratory scales. ET and increased levels of platelet-derived growth factors could cause renal sinuses fibrosis and glomerulopathy. In ET patients with renal sinuses\' fibrosis and glomerulopathy, initiating cytoreductive therapy could improve the outcome.